Photo-induced C-C reactions on insulators towards photolithography of graphene nanoarchitectures
2014 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 136, 4651-4658 p.Article in journal (Refereed) Published
On-surface chemistry for atomically precise sp2 macromolecules requires top-down lithographic methods on insulating surfaces in order to pattern the long-range complex architectures needed by the semiconductor industry. Here, we fabricate sp2-carbon nm-thin films on insulators and under ultra-high vacuum (UHV) conditions from photo-coupled brominated precursors. We reveal that covalent coupling is initiated by C-Br bond cleavage through photon energies exceeding 4.4 eV, as monitored by laser desorption ionization (LDI) mass spectrometry (MS) and X-ray photoelectron spectroscopy (XPS). Density functional theory (DFT) gives insight into the mechanisms of C-Br scission and C-C coupling processes. Further, unreacted material can be sublimed and the coupled sp2-carbon precursors can be graphitized by e-beam treatment at 500°C, demonstrating promising applications in photolithography of graphene nanoarchitectures. Our results present UV-induced reactions on insulators for the formation of all sp2-carbon architectures, thereby converging top-down lithography and bottom-up on-surface chemistry into technology.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2014. Vol. 136, 4651-4658 p.
Organic Chemistry Physical Chemistry Polymer Chemistry Theoretical Chemistry
IdentifiersURN: urn:nbn:se:liu:diva-104733DOI: 10.1021/ja412868wISI: 000333551800033OAI: oai:DiVA.org:liu-104733DiVA: diva2:698710